(19)
(11) EP 0 702 220 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.01.1997 Bulletin 1997/05

(43) Date of publication A2:
20.03.1996 Bulletin 1996/12

(21) Application number: 95306415.1

(22) Date of filing: 13.09.1995
(51) International Patent Classification (IPC)6: G01L 1/22, G01G 3/14
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 14.09.1994 JP 247303/94
14.09.1994 JP 247304/94

(71) Applicant: ISHIDA CO., Ltd.
Kyoto-shi, Kyoto 606 (JP)

(72) Inventors:
  • Naito, Kazufumi, c/o Ishida Co., Ltd.
    Ritto-cho, Kurita-Gun, Shiga 520-30 (JP)
  • Suzuki, Takao, c/o Ishida Co., Ltd.
    Ritto-cho, Kurita-Gun, Shiga 520-30 (JP)
  • Hijikata, Taro, c/o Ishida Co., Ltd.
    Ritto-cho, Kurita-Gun, Shiga 520-30 (JP)

(74) Representative: Skone James, Robert Edmund 
GILL JENNINGS & EVERY Broadgate House 7 Eldon Street
London EC2M 7LH
London EC2M 7LH (GB)

   


(54) Load cell and weighing apparatus using the same


(57) A load cell (3) includes a strain inducing element (5) having a fixed rigid body (5b) fixedly secured to a base support (4), and a plurality of transverse beams (5c, 5d) spaced one above the other and connecting the fixed and movable rigid bodies (5a, 5b) together. Each of the transverse beams (5c, 5d) has first and second strain generating areas (6) defined therein in spaced relation to each other at respective locations adjacent the fixed and movable rigid bodies (5a, 5b). A bridge circuit (8) for outputting a load signal of a magnitude proportional to strains generated at the strain generating areas (6) includes strain gauges (RA, RB, RC, RD) for detecting the strains generated at the strain generating areas (6), adjusting elements (TA, TB, TC, TD) for adjusting a balance of the bridge circuit (8), and lines (L) connecting them together. A circuit portion (8a) of the bridge circuit (8) which includes at least the strain gauge (RA, RB, RC, RD) and some of the lines (L) is formed in a predetermined pattern on one surface of the strain inducing element (5) so as to straddle between the first and second strain generating areas (6). Not only is the circuit portion symmetrical with respect to a point (O1) intermediate between the first and second strain generating areas (6), but also the strain inducing element (5) has left and right portions, including the fixed and movable rigid bodies (5a, 5b), which are symmetrical to each other.






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